The purpose of this work is to determine the enzymatic defect responsible for the various forms of glycogen storage diseases and other congenital disease related to carbohydrate metabolism, including inborn lysosomal diseases. Research will be continued in two directions: 1. Biopsies from patients will be analysed on the point of view of enzymatic activities and some of them will also be examined with the electron microscope. Experimental models of lysosomal overloading will also be investigated. 2. The regulation of liver glycogen metabolism and of gluconeogenesis by glucose, insulin, adrenergic agents, glucocorticoids and cyclic AMP will be further investigated.